GNU bug report logs - #79414
the ratio output by "gzip -l" is less than 0

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Message #5 received at submit <at> debbugs.gnu.org (full text, mbox):

From: shi xuantong <sxt1001 <at> outlook.com>
To: "bug-gzip <at> gnu.org" <bug-gzip <at> gnu.org>
Subject: the ratio output by "gzip -l" is less than 0
Date: Tue, 9 Sep 2025 15:02:50 +0000

[Message part 1 (text/plain, inline)]

gzip's version: 1.14
OS: openEuler
compiler:gcc-12.3.1

Reproduce steps:
echo "hiasdastysjdoyiojsad7saihdsd08y8768r" | gzip >> a.gz
gzip -l a.gz

result:

[cid:b070a7f1-da0a-4210-82e6-bd96683273d1]

[Message part 2 (text/html, inline)]

[image.png (image/png, inline)]

Message #10 received at 79414-done <at> debbugs.gnu.org (full text, mbox):

From: Paul Eggert <eggert <at> cs.ucla.edu>
To: shi xuantong <sxt1001 <at> outlook.com>
Cc: 79414-done <at> debbugs.gnu.org
Subject: Re: bug#79414: the ratio output by "gzip -l" is less than 0
Date: Tue, 9 Sep 2025 11:05:03 -0700

A negative compression ratio is correct when gzip's compressed output is 
larger than its input.

Arguably gzip should output "-Inf%" when the input is empty and the 
compressed output is not. But that's a mere nicety.

Message #13 received at 79414-done <at> debbugs.gnu.org (full text, mbox):

From: "Adler, Mark" <madler <at> alumni.caltech.edu>
To: "79414-done <at> debbugs.gnu.org" <79414-done <at> debbugs.gnu.org>
Cc: Paul Eggert <eggert <at> CS.UCLA.EDU>, shi xuantong <sxt1001 <at> outlook.com>
Subject: Re: bug#79414: the ratio output by "gzip -l" is less than 0
Date: Tue, 9 Sep 2025 18:12:35 +0000

[Message part 1 (text/plain, inline)]

pigz reports "-inf%”. Alas, a lower-case “i”.

On Sep 9, 2025, at 11:05 AM, Paul Eggert <eggert <at> CS.UCLA.EDU> wrote:

A negative compression ratio is correct when gzip's compressed output is larger than its input.

Arguably gzip should output "-Inf%" when the input is empty and the compressed output is not. But that's a mere nicety.

[Message part 2 (text/html, inline)]

Message #16 received at 79414 <at> debbugs.gnu.org (full text, mbox):

From: Paul Eggert <eggert <at> cs.ucla.edu>
To: "Adler, Mark" <madler <at> alumni.caltech.edu>
Cc: 79414 <at> debbugs.gnu.org, shi xuantong <sxt1001 <at> outlook.com>
Subject: Re: bug#79414: the ratio output by "gzip -l" is less than 0
Date: Tue, 9 Sep 2025 11:40:43 -0700

[Message part 1 (text/plain, inline)]

On 2025-09-09 11:12, Adler, Mark wrote:
> pigz reports "-inf%”. Alas, a lower-case “i”.

Thanks, good suggestion, I installed the attached into gzip.

[0001-gzip-report-Inf-for-negative-infinity.patch (text/x-patch, attachment)]

Message #19 received at 79414 <at> debbugs.gnu.org (full text, mbox):

From: shi xuantong <sxt1001 <at> outlook.com>
To: Paul Eggert <eggert <at> cs.ucla.edu>, "Adler, Mark" <madler <at> alumni.caltech.edu>
Cc: "79414 <at> debbugs.gnu.org" <79414 <at> debbugs.gnu.org>
Subject: Re: bug#79414: the ratio output by "gzip -l" is less than 0
Date: Wed, 10 Sep 2025 01:52:36 +0000

[Message part 1 (text/plain, inline)]

However, at this point, den is not zero. For the example provided in the email, den value is 37 and num value is -2

获取Outlook for Android<https://aka.ms/AAb9ysg>
________________________________
From: Paul Eggert <eggert <at> cs.ucla.edu>
Sent: Wednesday, September 10, 2025 2:40:43 AM
To: Adler, Mark <madler <at> alumni.caltech.edu>
Cc: shi xuantong <sxt1001 <at> outlook.com>; 79414 <at> debbugs.gnu.org <79414 <at> debbugs.gnu.org>
Subject: Re: bug#79414: the ratio output by "gzip -l" is less than 0

On 2025-09-09 11:12, Adler, Mark wrote:
> pigz reports "-inf%”. Alas, a lower-case “i”.

Thanks, good suggestion, I installed the attached into gzip.

[Message part 2 (text/html, inline)]

Message #22 received at 79414 <at> debbugs.gnu.org (full text, mbox):

From: shi xuantong <sxt1001 <at> outlook.com>
To: Paul Eggert <eggert <at> cs.ucla.edu>, "Adler, Mark" <madler <at> alumni.caltech.edu>
Cc: "79414 <at> debbugs.gnu.org" <79414 <at> debbugs.gnu.org>
Subject: Re: bug#79414: the ratio output by "gzip -l" is less than 0
Date: Wed, 10 Sep 2025 02:17:26 +0000

[Message part 1 (text/plain, inline)]

Apologies,please disregard my previous msg. I misunderstood it earlier.

获取Outlook for Android<https://aka.ms/AAb9ysg>
________________________________
From: shi xuantong <sxt1001 <at> outlook.com>
Sent: Wednesday, September 10, 2025 9:52:36 AM
To: Paul Eggert <eggert <at> cs.ucla.edu>; Adler, Mark <madler <at> alumni.caltech.edu>
Cc: 79414 <at> debbugs.gnu.org <79414 <at> debbugs.gnu.org>
Subject: Re: bug#79414: the ratio output by "gzip -l" is less than 0

However, at this point, den is not zero. For the example provided in the email, den value is 37 and num value is -2

获取Outlook for Android<https://aka.ms/AAb9ysg>
________________________________
From: Paul Eggert <eggert <at> cs.ucla.edu>
Sent: Wednesday, September 10, 2025 2:40:43 AM
To: Adler, Mark <madler <at> alumni.caltech.edu>
Cc: shi xuantong <sxt1001 <at> outlook.com>; 79414 <at> debbugs.gnu.org <79414 <at> debbugs.gnu.org>
Subject: Re: bug#79414: the ratio output by "gzip -l" is less than 0

On 2025-09-09 11:12, Adler, Mark wrote:
> pigz reports "-inf%”. Alas, a lower-case “i”.

Thanks, good suggestion, I installed the attached into gzip.

[Message part 2 (text/html, inline)]

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